Spans in math

11 files changed, 100 insertions, 35 deletions

diff --git a/library/src/math/accent.rs b/library/src/math/accent.rs
index 03caf411..9ef76279 100644
--- a/library/src/math/accent.rs
+++ b/library/src/math/accent.rs
@@ -66,7 +66,7 @@ impl LayoutMath for AccentNode {
         // Forcing the accent to be at least as large as the base makes it too
         // wide in many case.
         let Accent(c) = self.accent();
-        let glyph = GlyphFragment::new(ctx, c);
+        let glyph = GlyphFragment::new(ctx, c, self.span());
         let short_fall = ACCENT_SHORT_FALL.scaled(ctx);
         let variant = glyph.stretch_horizontal(ctx, base.width(), short_fall);
         let accent = variant.frame;
diff --git a/library/src/math/ctx.rs b/library/src/math/ctx.rs
index 991d582c..bd44546d 100644
--- a/library/src/math/ctx.rs
+++ b/library/src/math/ctx.rs
@@ -124,13 +124,15 @@ impl<'a, 'b, 'v> MathContext<'a, 'b, 'v> {
             .into_frame())
     }
 
-    pub fn layout_text(&mut self, text: &str) -> SourceResult<()> {
+    pub fn layout_text(&mut self, node: &TextNode) -> SourceResult<()> {
+        let text = node.text();
+        let span = node.span();
         let mut chars = text.chars();
         if let Some(glyph) = chars
             .next()
             .filter(|_| chars.next().is_none())
             .map(|c| self.style.styled_char(c))
-            .and_then(|c| GlyphFragment::try_new(self, c))
+            .and_then(|c| GlyphFragment::try_new(self, c, span))
         {
             // A single letter that is available in the math font.
             if self.style.size == MathSize::Display
@@ -146,7 +148,7 @@ impl<'a, 'b, 'v> MathContext<'a, 'b, 'v> {
             let mut fragments = vec![];
             for c in text.chars() {
                 let c = self.style.styled_char(c);
-                fragments.push(GlyphFragment::new(self, c).into());
+                fragments.push(GlyphFragment::new(self, c, span).into());
             }
             let frame = MathRow::new(fragments).to_frame(self);
             self.push(FrameFragment::new(self, frame));
@@ -158,7 +160,7 @@ impl<'a, 'b, 'v> MathContext<'a, 'b, 'v> {
                 style = style.with_italic(false);
             }
             let text: EcoString = text.chars().map(|c| style.styled_char(c)).collect();
-            let frame = self.layout_content(&TextNode::packed(text))?;
+            let frame = self.layout_content(&TextNode::packed(text).spanned(span))?;
             self.push(
                 FrameFragment::new(self, frame)
                     .with_class(MathClass::Alphabetic)
diff --git a/library/src/math/delimited.rs b/library/src/math/delimited.rs
index 6f468af7..2b9ee5ed 100644
--- a/library/src/math/delimited.rs
+++ b/library/src/math/delimited.rs
@@ -89,7 +89,9 @@ fn scale(
     ) {
         let glyph = match fragment {
             MathFragment::Glyph(glyph) => glyph.clone(),
-            MathFragment::Variant(variant) => GlyphFragment::new(ctx, variant.c),
+            MathFragment::Variant(variant) => {
+                GlyphFragment::new(ctx, variant.c, variant.span)
+            }
             _ => return,
         };
 
diff --git a/library/src/math/frac.rs b/library/src/math/frac.rs
index 0624832a..f670159d 100644
--- a/library/src/math/frac.rs
+++ b/library/src/math/frac.rs
@@ -32,7 +32,7 @@ pub struct FracNode {
 
 impl LayoutMath for FracNode {
     fn layout_math(&self, ctx: &mut MathContext) -> SourceResult<()> {
-        layout(ctx, &self.num(), &self.denom(), false)
+        layout(ctx, &self.num(), &self.denom(), false, self.span())
     }
 }
 
@@ -58,7 +58,7 @@ pub struct BinomNode {
 
 impl LayoutMath for BinomNode {
     fn layout_math(&self, ctx: &mut MathContext) -> SourceResult<()> {
-        layout(ctx, &self.upper(), &self.lower(), true)
+        layout(ctx, &self.upper(), &self.lower(), true, self.span())
     }
 }
 
@@ -68,6 +68,7 @@ fn layout(
     num: &Content,
     denom: &Content,
     binom: bool,
+    span: Span,
 ) -> SourceResult<()> {
     let short_fall = DELIM_SHORT_FALL.scaled(ctx);
     let axis = scaled!(ctx, axis_height);
@@ -121,9 +122,13 @@ fn layout(
     frame.push_frame(denom_pos, denom);
 
     if binom {
-        ctx.push(GlyphFragment::new(ctx, '(').stretch_vertical(ctx, height, short_fall));
+        ctx.push(
+            GlyphFragment::new(ctx, '(', span).stretch_vertical(ctx, height, short_fall),
+        );
         ctx.push(FrameFragment::new(ctx, frame));
-        ctx.push(GlyphFragment::new(ctx, ')').stretch_vertical(ctx, height, short_fall));
+        ctx.push(
+            GlyphFragment::new(ctx, ')', span).stretch_vertical(ctx, height, short_fall),
+        );
     } else {
         frame.push(
             line_pos,
diff --git a/library/src/math/fragment.rs b/library/src/math/fragment.rs
index de456b82..87e28555 100644
--- a/library/src/math/fragment.rs
+++ b/library/src/math/fragment.rs
@@ -147,21 +147,22 @@ pub struct GlyphFragment {
     pub style: MathStyle,
     pub font_size: Abs,
     pub class: Option<MathClass>,
+    pub span: Span,
 }
 
 impl GlyphFragment {
-    pub fn new(ctx: &MathContext, c: char) -> Self {
+    pub fn new(ctx: &MathContext, c: char, span: Span) -> Self {
         let id = ctx.ttf.glyph_index(c).unwrap_or_default();
-        Self::with_id(ctx, c, id)
+        Self::with_id(ctx, c, id, span)
     }
 
-    pub fn try_new(ctx: &MathContext, c: char) -> Option<Self> {
+    pub fn try_new(ctx: &MathContext, c: char, span: Span) -> Option<Self> {
         let c = ctx.style.styled_char(c);
         let id = ctx.ttf.glyph_index(c)?;
-        Some(Self::with_id(ctx, c, id))
+        Some(Self::with_id(ctx, c, id, span))
     }
 
-    pub fn with_id(ctx: &MathContext, c: char, id: GlyphId) -> Self {
+    pub fn with_id(ctx: &MathContext, c: char, id: GlyphId, span: Span) -> Self {
         let advance = ctx.ttf.glyph_hor_advance(id).unwrap_or_default();
         let italics = italics_correction(ctx, id).unwrap_or_default();
         let bbox = ctx.ttf.glyph_bounding_box(id).unwrap_or(Rect {
@@ -192,6 +193,7 @@ impl GlyphFragment {
                 ':' => Some(MathClass::Relation),
                 _ => unicode_math_class::class(c),
             },
+            span,
         }
     }
 
@@ -208,6 +210,7 @@ impl GlyphFragment {
             font_size: self.font_size,
             italics_correction: self.italics_correction,
             class: self.class,
+            span: self.span,
         }
     }
 
@@ -222,7 +225,7 @@ impl GlyphFragment {
                 c: self.c,
                 x_advance: Em::from_length(self.width, self.font_size),
                 x_offset: Em::zero(),
-                span: Span::detached(),
+                span: self.span,
                 offset: 0,
             }],
         };
@@ -249,6 +252,7 @@ pub struct VariantFragment {
     pub style: MathStyle,
     pub font_size: Abs,
     pub class: Option<MathClass>,
+    pub span: Span,
 }
 
 impl Debug for VariantFragment {
diff --git a/library/src/math/matrix.rs b/library/src/math/matrix.rs
index 6dec645c..148d79e8 100644
--- a/library/src/math/matrix.rs
+++ b/library/src/math/matrix.rs
@@ -36,7 +36,13 @@ impl LayoutMath for VecNode {
     fn layout_math(&self, ctx: &mut MathContext) -> SourceResult<()> {
         let delim = self.delim(ctx.styles());
         let frame = layout_vec_body(ctx, &self.children(), Align::Center)?;
-        layout_delimiters(ctx, frame, Some(delim.open()), Some(delim.close()))
+        layout_delimiters(
+            ctx,
+            frame,
+            Some(delim.open()),
+            Some(delim.close()),
+            self.span(),
+        )
     }
 }
 
@@ -112,7 +118,13 @@ impl LayoutMath for MatNode {
     fn layout_math(&self, ctx: &mut MathContext) -> SourceResult<()> {
         let delim = self.delim(ctx.styles());
         let frame = layout_mat_body(ctx, &self.rows())?;
-        layout_delimiters(ctx, frame, Some(delim.open()), Some(delim.close()))
+        layout_delimiters(
+            ctx,
+            frame,
+            Some(delim.open()),
+            Some(delim.close()),
+            self.span(),
+        )
     }
 }
 
@@ -152,7 +164,7 @@ impl LayoutMath for CasesNode {
     fn layout_math(&self, ctx: &mut MathContext) -> SourceResult<()> {
         let delim = self.delim(ctx.styles());
         let frame = layout_vec_body(ctx, &self.children(), Align::Left)?;
-        layout_delimiters(ctx, frame, Some(delim.open()), None)
+        layout_delimiters(ctx, frame, Some(delim.open()), None, self.span())
     }
 }
 
@@ -288,6 +300,7 @@ fn layout_delimiters(
     mut frame: Frame,
     left: Option<char>,
     right: Option<char>,
+    span: Span,
 ) -> SourceResult<()> {
     let axis = scaled!(ctx, axis_height);
     let short_fall = DELIM_SHORT_FALL.scaled(ctx);
@@ -296,14 +309,17 @@ fn layout_delimiters(
     frame.set_baseline(height / 2.0 + axis);
 
     if let Some(left) = left {
-        ctx.push(GlyphFragment::new(ctx, left).stretch_vertical(ctx, target, short_fall));
+        ctx.push(
+            GlyphFragment::new(ctx, left, span).stretch_vertical(ctx, target, short_fall),
+        );
     }
 
     ctx.push(FrameFragment::new(ctx, frame));
 
     if let Some(right) = right {
         ctx.push(
-            GlyphFragment::new(ctx, right).stretch_vertical(ctx, target, short_fall),
+            GlyphFragment::new(ctx, right, span)
+                .stretch_vertical(ctx, target, short_fall),
         );
     }
 
diff --git a/library/src/math/mod.rs b/library/src/math/mod.rs
index c11bea79..0cc7f43c 100644
--- a/library/src/math/mod.rs
+++ b/library/src/math/mod.rs
@@ -264,7 +264,7 @@ impl LayoutMath for Content {
         }
 
         if let Some(node) = self.to::<TextNode>() {
-            ctx.layout_text(&node.text())?;
+            ctx.layout_text(node)?;
             return Ok(());
         }
 
diff --git a/library/src/math/root.rs b/library/src/math/root.rs
index cb01e6a1..1ab99b2b 100644
--- a/library/src/math/root.rs
+++ b/library/src/math/root.rs
@@ -18,7 +18,7 @@ pub struct SqrtNode {
 
 impl LayoutMath for SqrtNode {
     fn layout_math(&self, ctx: &mut MathContext) -> SourceResult<()> {
-        layout(ctx, None, &self.radicand())
+        layout(ctx, None, &self.radicand(), self.span())
     }
 }
 
@@ -44,7 +44,7 @@ pub struct RootNode {
 
 impl LayoutMath for RootNode {
     fn layout_math(&self, ctx: &mut MathContext) -> SourceResult<()> {
-        layout(ctx, Some(&self.index()), &self.radicand())
+        layout(ctx, Some(&self.index()), &self.radicand(), self.span())
     }
 }
 
@@ -55,6 +55,7 @@ fn layout(
     ctx: &mut MathContext,
     mut index: Option<&Content>,
     radicand: &Content,
+    span: Span,
 ) -> SourceResult<()> {
     let gap = scaled!(
         ctx,
@@ -80,7 +81,7 @@ fn layout(
             frame
         })
         .unwrap_or_else(|| {
-            let glyph = GlyphFragment::new(ctx, '√');
+            let glyph = GlyphFragment::new(ctx, '√', span);
             glyph.stretch_vertical(ctx, target, Abs::zero()).frame
         });
 
@@ -145,7 +146,7 @@ fn precomposed(ctx: &MathContext, index: Option<&Content>, target: Abs) -> Optio
     };
 
     ctx.ttf.glyph_index(c)?;
-    let glyph = GlyphFragment::new(ctx, c);
+    let glyph = GlyphFragment::new(ctx, c, node.span());
     let variant = glyph.stretch_vertical(ctx, target, Abs::zero()).frame;
     if variant.height() < target {
         return None;
diff --git a/library/src/math/stretch.rs b/library/src/math/stretch.rs
index 1c994802..7ba6e5c1 100644
--- a/library/src/math/stretch.rs
+++ b/library/src/math/stretch.rs
@@ -73,7 +73,7 @@ fn stretch_glyph(
 
     // This is either good or the best we've got.
     if short_target <= best_advance || construction.assembly.is_none() {
-        return GlyphFragment::with_id(ctx, base.c, best_id).to_variant();
+        return GlyphFragment::with_id(ctx, base.c, best_id, base.span).to_variant();
     }
 
     // Assemble from parts.
@@ -142,7 +142,7 @@ fn assemble(
             advance += ratio * (max_overlap - min_overlap);
         }
 
-        let fragment = GlyphFragment::with_id(ctx, base.c, part.glyph_id);
+        let fragment = GlyphFragment::with_id(ctx, base.c, part.glyph_id, base.span);
         selected.push((fragment, advance));
     }
 
@@ -181,6 +181,7 @@ fn assemble(
         font_size: base.font_size,
         italics_correction: Abs::zero(),
         class: base.class,
+        span: base.span,
     }
 }
 
diff --git a/library/src/math/underover.rs b/library/src/math/underover.rs
index a723ae97..cfbb30b6 100644
--- a/library/src/math/underover.rs
+++ b/library/src/math/underover.rs
@@ -22,7 +22,7 @@ pub struct UnderlineNode {
 
 impl LayoutMath for UnderlineNode {
     fn layout_math(&self, ctx: &mut MathContext) -> SourceResult<()> {
-        layout(ctx, &self.body(), &None, '\u{305}', LINE_GAP, false)
+        layout(ctx, &self.body(), &None, '\u{305}', LINE_GAP, false, self.span())
     }
 }
 
@@ -44,7 +44,7 @@ pub struct OverlineNode {
 
 impl LayoutMath for OverlineNode {
     fn layout_math(&self, ctx: &mut MathContext) -> SourceResult<()> {
-        layout(ctx, &self.body(), &None, '\u{332}', LINE_GAP, true)
+        layout(ctx, &self.body(), &None, '\u{332}', LINE_GAP, true, self.span())
     }
 }
 
@@ -70,7 +70,15 @@ pub struct UnderbraceNode {
 
 impl LayoutMath for UnderbraceNode {
     fn layout_math(&self, ctx: &mut MathContext) -> SourceResult<()> {
-        layout(ctx, &self.body(), &self.annotation(ctx.styles()), '⏟', BRACE_GAP, false)
+        layout(
+            ctx,
+            &self.body(),
+            &self.annotation(ctx.styles()),
+            '⏟',
+            BRACE_GAP,
+            false,
+            self.span(),
+        )
     }
 }
 
@@ -96,7 +104,15 @@ pub struct OverbraceNode {
 
 impl LayoutMath for OverbraceNode {
     fn layout_math(&self, ctx: &mut MathContext) -> SourceResult<()> {
-        layout(ctx, &self.body(), &self.annotation(ctx.styles()), '⏞', BRACE_GAP, true)
+        layout(
+            ctx,
+            &self.body(),
+            &self.annotation(ctx.styles()),
+            '⏞',
+            BRACE_GAP,
+            true,
+            self.span(),
+        )
     }
 }
 
@@ -122,7 +138,15 @@ pub struct UnderbracketNode {
 
 impl LayoutMath for UnderbracketNode {
     fn layout_math(&self, ctx: &mut MathContext) -> SourceResult<()> {
-        layout(ctx, &self.body(), &self.annotation(ctx.styles()), '⎵', BRACKET_GAP, false)
+        layout(
+            ctx,
+            &self.body(),
+            &self.annotation(ctx.styles()),
+            '⎵',
+            BRACKET_GAP,
+            false,
+            self.span(),
+        )
     }
 }
 
@@ -148,7 +172,15 @@ pub struct OverbracketNode {
 
 impl LayoutMath for OverbracketNode {
     fn layout_math(&self, ctx: &mut MathContext) -> SourceResult<()> {
-        layout(ctx, &self.body(), &self.annotation(ctx.styles()), '⎴', BRACKET_GAP, true)
+        layout(
+            ctx,
+            &self.body(),
+            &self.annotation(ctx.styles()),
+            '⎴',
+            BRACKET_GAP,
+            true,
+            self.span(),
+        )
     }
 }
 
@@ -160,10 +192,11 @@ fn layout(
     c: char,
     gap: Em,
     reverse: bool,
+    span: Span,
 ) -> SourceResult<()> {
     let gap = gap.scaled(ctx);
     let body = ctx.layout_row(body)?;
-    let glyph = GlyphFragment::new(ctx, c);
+    let glyph = GlyphFragment::new(ctx, c, span);
     let stretched = glyph.stretch_horizontal(ctx, body.width(), Abs::zero());
 
     let mut rows = vec![body, stretched.into()];
diff --git a/library/src/meta/heading.rs b/library/src/meta/heading.rs
index e82f80c6..47047927 100644
--- a/library/src/meta/heading.rs
+++ b/library/src/meta/heading.rs
@@ -107,6 +107,7 @@ impl Synthesize for HeadingNode {
 
         let node = self
             .clone()
+            .with_level(self.level(styles))
             .with_outlined(self.outlined(styles))
             .with_numbers(numbering.is_some().then(|| counter.take()))
             .with_numbering(numbering)